1. Field of the Invention
The present invention relates to the sequence of movement of molds in a fixed surface forming machine which maximizes the production capacity of the forming plant keeping cost low in by substantially reducing the requirements of physical space typically associated with an increase in production.
2. Description of The Related Art
In every chocolate forming plant, molds are used which have cavities that defined the shape of the product to be formed. The forming process in a chocolate forming plant in general includes three stages: deposit of chocolate in the mold cavities, cooling of the chocolate, and removal of cooled chocolate shapes from the mold.
Cooling is effected in tunnels which are refrigerated at a temperature of close to 5.degree. C. The time that the mold is retained within the cooling tunnel depends on three factors: the thickness of the chocolate bar, the surface exposed to the cold and the cooling capacity of the tunnel. There is, however, a minimum residence time given by the very nature of the product. For example, chocolate should not be cooled to a temperature under 0.degree. C to avoid condensation and loss of brightness. In addition, because of the fatty material content of chocolate, the temperature decrease will not be immediate. Indeed, chocolate has a thermal inertia that requires a predetermined minimum cooling period inside the tunnel.
Depending upon the type of chocolate forming plant, the movement of the mold is achieved by one of three systems. The first is a dragging chain which moves the entire line of molds in the chocolate forming plant. Mold carrying frames are attached to the links of the chain and thus maintain each mold fixed in its position.
The second system for moving molds is a conveyor belt that displaces the mold without using mold carrying frames.
Finally, there is the fixed surface system wherein it is the molds that are displaced on a fixed surface.
In conveyor chain and conveyor belt systems the molds are conveyed because the surface, either of the chain or the belt, is in motion. In the fixed surface system, on the other hand, the molds are located on a smooth, fixed surface and the molds are pushed by a hydraulic, pneumatic or other mechanical system located at the end of the line. The molds push one another continuously. All three systems typically move one mold after the other.
In any chocolate forming plant using the "shell" system, the sequence of the movement of the molds is as follows:
______________________________________ Process No. of Molds ______________________________________ Chocolate deposit 1 Dumping of molds and "shell" 1 forming Cleaning edges of mold shells 1 Sequentially cooling molds 1 Filling molds 1 Cooling mold and filling 1 or 2 Total filling of mold 1 Cleaning surface of filled mold 1 Cooling of filled, cleaned molds 1 or more ______________________________________
The aforementioned systems present some disadvantages regarding the efficient use of the deposit relation, "shell" formation and cooling tunnels.
When the displacement of the mold is carried out by means of dragging chains or conveyor belt, to minimize the space required for the cooling tunnels, vertical tunnels with mold elevators are used and the same chain or belt is used to lift and displace the mold along the upwards and downwards run inside a vertical cooling tunnel.
However, vertical tunnels are very expensive, difficult to regulate and molds frequently become stuck inside the vertical cooling tunnel.
When the mold are themselves displaced on a fixed surface, the use of vertical tunnels is avoided but this requires the use of very long cooling tunnel(s) as the molds move in sequence without changing level. As a result, the forming plant requires a great deal of space for the cooling tunnel(s).